Electrode for welding.



Y UNITED 1 STATE-s PATENT oEEIoE.

ALBERT B. HERR-ICR, or N Ew YORK; N. Y.,' assIerNoR To TH E ELECTRIC RAILWAY IMPROVEMENT COMPANY, or cLEvELANnoHIo, A CORPORATION or OHIO.

ELECTRODE FO WELDING.

To all whom may concern:

Be it lInown thatI, ALBERT B. HERRICK,

`a citizen of the United States, and a resident'.y -ot' New York, county of New York and State vLetters Patent No. 1,012,077, issued to me December 19, 1911, it is highly desirable to avoid having. an arc play between the electrode and the article being heatedfwhere such article is of the l-low fusing character of the bond referred to specifically in said patent. There is a tendency, however, for the current to thus arc across even atrelatively low voltage incidentally to bringing up the electrode into proximity with the terminal; while with a direct current at the relative high voltage ordinarily employed,.

for example, in electric railway operation, it has been found quite out ofthe question to utilize suchurrent for heatlng'the welding electrode without irst transforming the same and Steppin it down.

The'object oft e presentinvention is to providean electrode in which `not only may the tendency to arc be e'liminatedwhere the low voltage at present in use'is employed, but also render it possible to satisfactorily use a much higher voltage than is at present employed in connection with such patented process or in prevailing methods of bonding by the use ofelectrically generated heat. To the accomplishment of this and related ends,

' said invention, then, consists of the means hereinafter fully described and particularl pointed out in the claims.

'Ihe annexed drawing `and the following i description set forth iridata-il certain mecha- `nism embodying the invention, such vdisclosed means constituting, however, but one of various mechanical forms in which the principle of the invention may be used.

In said annexed drawing :-F igure 1 is a diagrammatic representation of an a'. paratus, including m improved electro e, ar-l gwelding, as for example In welding. a bond ranged for bon ing; that is, for welding specification of Letters raient.

Patent-d Aug. 4, 1914.

Application filed November 29, `1912. Serial No. 733,973.A

bonds onto steel Trails, using the regular trolley current; F ig.v 2 Vis a' perspective view vof said electrode; and Fig. 3 is a transverse crosssection thereof.

Referring tothe several figuresl of the Idrawing and especially Fig. 3, the electrode therein illustrated will bel seen to differ from. the previous substantially solid electrode of uniform composition'throughout, in that it is builtup of two bodies or members of diverse materials, one bony l designed for contacting with the hond and the otherfbody 2 backing such first body. Thelatter'A is preferabl)7 composed of granular material and is held ina suitable holder 3 of insulating material, that forms the main support for the body 1 that directly contacts with the bond, as well. This cont-acting body, on the contrary, is formed in a compact or solidmass and corresponds more nearly with the electrode as at present constructed. It is desirable, however, that it have a higher specific resistance than the charging or backing material, and` to this end thev chief constitutent of the former is amorphous carbon, while that of the latter is graphitic- Carbon. i

A satisfactory formula for the composi tion of the charging mixture has been found by experiment to be as follows, viz., 25 parts of flaked graphite, 1() parts of French chalk and 10 parts of fullers earth mixed with molasses, baked until the latter is carbonated, and then ground Vinto a granular state. Similarly va recommended formula for the composition of the contact plate of the electrode is 10 parts ocarbon (medium granulated), six pai-ts of powdered asbestos, l

.two distinctive elements or ingredients in the respective parts of the electrode being graphitic and amorphous carbon, the one will disrupt the arc in the other,the charging or backing material having the lower specific resistance.

In employing the foregoing electrode in lie at the baclr of this recess, the mass `2 of temperature such energy absorption becomes nected. This lead isbrought direct from -volved inthe operation of the foregoing aponlyafslow'rise intemperature will occur; l but, where the resistance of the medium to to suchA absorption, are both correspondingly increased. The absorption of'such energy becomes-apparent by the increasing lumibe utilized as a means for fusing; such coning tol such resistance or heating medium the Y down their chemical union with the result- L nice onto a steel rail1 'the terminal of the bond is held against the rail face the desired point of junction, by bringing up the electrode and pressingthe saine .against said terminal.v rllie. face of the electrode thus pressed against the bond is preferably recessed, as ata, to partially receive the bond terminal and conform vit to the desired shape after fusion-occurs. rllie plate-like body l will then granular material bach of said plate being packed with suoli pressure as is desired by a plug-like conductor member 5 with which the lead 6 supplying1 the current is contlie trolley 7, or other source of current with ln. further explanation of the action inp aratus,`it ina-y be stated that the physical characteristics vof the material usedy in the .conductionV of curreir; for heat-ing purposes have marked effect on the forni this energy absorption ,in the resistance medium will. take. ald/'hen the energy losses are low, due to the high conductivityv of the medium,

the iiow `of the current is greater, 4the anio'unt'of venergy absorbed, 'and the rate of increase in the temperature of the body due nostyl of the resistance medium, and at this useful in breaking" down the mechanical structure of metal to be welded and in raisinny to a melting'point bodies,such as metals, in Contact with the heating'surface thus provided, so that such resistance -inediuin may tacting metallic bodyor -for welding or homogeneously joining the same to another body.` Certain dii'iiculties, however, arise when a `current of small volume vand high 'potential is used for thepurpose of supplynecessar'y energy for bringing the latter to the desired temperature, and so far as advised it has never heretofore been found feasible in practice atleast to utilize acurrent of thisY sort in heating' a Welding,f elec trode of any considerable area, or in producing thereby a junction between metallic bodies which might truly be called homogeneous rlhe normal action of a resistance medium, when heated by a current of large volume and low potential, is to come up to a state of incandescence without a breake down of its material structure, there being in such case insuliicient potential between adjacent particles 'of vtlieniedium 'to break ant formation of a gas, or in other words the volatilization of the medium, suoli volatilization producing wliateis known as anY 'across the resistance medium is large, so

that suiiicient potential or energy may occur between adjacent particles or molecules in 'ally punctured through the medium. The

energy manifestation of the current is then changed in its character, .such-energy being dissipatedL yin these limited channels Where the break-down in the material has occurred,

'boiling or volatilizing' the material directly afected, while the temperature of the'electrode as a whole falls, since the arcingg` paths present relatively lower resistance for the conduction of the current than d0 the remailling portions of the electrode. By the improved construction of electrode, how-` harmful results just noted as occurringv when a current of high potential is utilized in connection with an ordinary electrode. By constructing the electrode of lamin disposed transversely, that is substantially `at right langles to the direction of current` How through the electrode, which laminae di'er either vin their physical character, or in their composition, or in both these particulars, as in the case of the specific construction herein-before described, the harinful arci'ng' within the medium will not occur `to defeat the purpose of the operation.` it

is thus rendered possible to utilize a high tension current for welding without reducing' such current t0 a lower potential and greater volume, as has heretofore been themselves readily tothe creation of arcing within the medium, silica and aluminum oXid apparently having the most marked influence in tending to form incipient arcs and s facilitating their growth, whereas limes, clay and carbonaceous materials have been found to present .greater resistance to this effect.

Further, l have found that Where thev resistance medium is of uniform composition throughout, even though composed of heteroil: welding electrode comprising laminae dis-v niemeer 3 conductivity in a mai-lied degree. However,

utilising different combinations of materials in the construction of the electrode and disposing these in more or less distii'ict lay rs or laminze extending transversely n lsect to the line of flow of the current, ermore making the physical charich layers different, as for example acl er of making one a solid mass and the other of granula composition, this tendency to form arcs substantially entirely eliminated, even with a current of the voltage regularly employed "i the ope-ration of electric railways, and the 'iplication of such current directly to the oonding cperatuin licreinbefore described rendered possible. It is, ofcourse, not intended by the specific reference just made to this yone field of use, to imply that the principle of operation involved is notv susceptible of much `wider application in the art of Welding or heating by means of the electric current, nor is it meant to imply that the specific formulae given for the composi-V tion of the two layers or strata, of which the electrode has been described as consisting,

are the only formulae which may be used, these merely being the ones which have been found to give the best results. in' thecourse` of a number of experimentswith various elements.

Other` modes of applying the principleof my invention may be employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed. I therefore particularly point out and distinctly claim as my invention :f

`l. As a new article of manufacture, a welding electrode of laminated structurethe `l-L'iininecJ being disposed transversely of Lthe `line of current flow through said electrode.'

,2. As new article of manufact-ure, a

posed transversely of the line of current flow through said electrode, such lamiiiae being of different physical character.

3. a new article of manufacture, a welding electrode comprising laminee disposed transversely of the line of current flow through said electrode, one of said laminze being of relatively solid, the other of granular, character.

` l. As a new article of manufacture, a welding electrode comprising laminas disposed transversely of the line of current flow through said electrode, the one of said laminae designed to Contact with the article to be welded being of relatively solid, the other of granular, character.

5. As a new article of manufacture, a welding electrode comprising laminaedisposed transversely of the line of current flow through said electrode, sucli'laniinae being of unlike chemical composition.

G. As a new article of manufacture, a

welding electrode comprising lamin dis-` posed transversely of the line of current flow through said electrode, one of said lamina@ having a higher specific resistance than the other.

7. As a new article of manufacture, a welding electrode comprising laminae disposed transversely' of the line of current flow throughsaid electrode, one of said laminati` having as its chief constituent amorphous carbon, the other having as its chief con-' stituent grapliitic carbon.

8. As a new article of manufacture, a welding electrode comprising laminze dis'- posed transversely of the line of current flow through said electrode,the one of said laminae designed to contact with the article to be welded having as its chief constituent amorphous carbon, the other having as its chief constituent graphitic carbon.

19.' As a new article of manufacture, a welding electrode comprising a holder of insulating material, a plate of solid resistance material secured in said holder so as to be adapted to contact with the.article to be welded, a body of granular resistance material back of and in contact with said plate;

and connections for passing an electric current through saidpbo'dy of granular material and plate.

l0. As a new article of manufacture, a` welding electrode comprising a holder of insulating material provided with a recess in its face adapted to receive the article to be welded, a plate of resistance material secured in said holder and forming the rear wall of such recess, a body of'granular resistance.

material back of and in contact with said plate; and connections for passing an electric current through said body of granular material and plate. Signedby me this 26th day of November,

ALBERT B. HERRICK. Attested by- D. L. Davies, JNO. F. OBERLIN. 

